A microcomputer-based system that permits the decaying value of the radionuclide in a syringe to be continuously displayed in the patient imaging area after a single calibration is performed in radiopharmacy. This design involves the conversion of a single-user system in the Scanditronix imaging area to a multi-monitor, multi-user system to work simultaneously on patients in the Neuropet, Scanditronix and Posicam imaging areas.